Due to recent advances in digital signal processing and communications technology, radio and TV broadcast signals are provided gradually in the form of digital data. As signals are provided in the form of digital data, a variety of information is now allowed to be added to TV or radio broadcast signals, the information including news, stock, weather, traffic, and so on.
Meanwhile, traffic congestion is commonly observed due to increase of the number of vehicles in downtown areas and the number of holiday vehicles during holidays. The increase of the number of vehicles accelerates environmental pollution; thus, using public transportation is highly recommended by government authorities. In order to have a citizen use public transportation on his or her own will, use of public transportation should also be more comfortable and service hours thereof should be predictable. For this purpose, public transportation means moving with private vehicles on the road such as a bus should provide service information and information about change of service hours due to road conditions. Also, necessary is providing information about connection among different types of public transportation means (e.g., between a bus and a subway train) and thus enabling the citizen to transfer among different types of public transportation means conveniently and quickly to facilitate public transportation usage. This is because in a big city, it is difficult to arrive at a destination by using public transportation means of a single kind alone.
Provision of public transportation information requires a standard format because a plurality of terminals made by different manufacturers should be able to detect broadcast digital transportation information and interpret the information in the same way for the user.